[Blocked] Developer joy: Add files when running Cyperful

[justinlittman]

Blocked by XHR bug in Cyperful: stepful/cyperful#7

Currently the approach for adding files to the dropzone (find('.dropzone').drop('spec/fixtures/files/hippo.png')) doesn't work with Cyperful.

It would spark developer joy if those tests still worked with Cyperful. So, either figure out why it doesn't work or come up with an approach that does (perhaps when running a test with Cyperful render a plain-old file input).